Flow control device for hollowshafted auger



J. E. BATTEN 3,529,428

FLOW CONTROL DEVICE FOR HOLLOW-SHAFTED AUGBR Sept. 22, 1970 Filed April, 17, 1968 F/eiZ IE v i w I. A E

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m 5 a m M United States Patent Office 3,529,428 Patented Sept. 22, 1970 3,529,428 FLOW CONTROL DEVICE FOR HOLLOW- SHAFTED AUGER John Earl Batten, Orlando, Fla., assignor to Foundation Services, Incorporated, Orlando, Fla., a corporation of Florida Filed Apr. 17, 1968, Ser. No. 722,091 Int. Cl. E02d 5/36; E21b 9/06 US. Cl. 6163 5 Claims ABSTRACT OF THE DISCLOSURE This invention deals with an improvement in hollowshafted augers used for drilling and placing cast-in-situ piling. A circumferential cup is slideably attached to the axial extremity of the hollow shaft. When telescoped into the closed position, this cup abuts the axial extremity of the shaft and prevents flow of fluid material out of the opening. When axially extended, a fluid flow path is created from the axial extremity of the shaft through apertures cut in the circumferential surface of the cup. Flow deflectors guide the flowing cementitious grout from the axial extremity of the shaft to these apertures to prevent the formation of a solidified build-up. The device is held closed during drilling by the upward pressure of the medium into which the auger is penetrating. Opening of the device is accomplished by the combined forces of gravity andgrout pressure.

BACKGROUND OF THE INVENTION This invention relates to apparatus which may be used in the installation of cast-in-situ piling by drilling and injecting cementitious fluid through the hollow shaft of the drilling auger and to the method of using such apparatus.

Patterson in US. Pat. 2,729,067 discloses a method for placing cast-in-situ piles. Although Patterson expresses a preference for injecting the cementitious grout through an auxiliary pipe inserted into the soil adjacent to the hole drilled by an auger, he also discloses the use of a hollowshafted auger for this purpose. Ryser et al., in US. Pat. 2,920,455, also disclose the use of hollow-shafted augers for this general purpose.

One disadvantage in using all of the methods heretofore known, including those of the cited references, for the placing of cast-in-situ piling is that they lack reliable means for selectively opening and closing the conduit formed by the hollow-shafted auger to the passage of fluid material at the point at which that fluid is to be injected into the soil or other medium into which the auger is being sunk, i.e. adjacent to the zone of deepest penetration of the auger.

One procedure used for this purpose isto permit the hollow shaft of the auger to become filled with soil during the drilling step and then to rely on grout pumping pressure to discharge this soil from the inside of the shaft. The possibility of clogging the shaft and the likelihood that the initially injected grout will be adulterated with soil which entered the shaft during drilling are but two of the disadvantages of this method.

Another expedient which has been used is to insert a stopper-like plug in the axial extremity of the hollow shaft. In the Patterson reference, this plug is held in place with shear pins which are parted by the initial surge of grout pumping pressure, thereby expelling the plug. Another procedure involves holding the plug in the sealing position in the shaft by the use of a chain or cable extending through the hollow shaft until the pumping of grout is commenced.

A disadvantage of all of these closing devices is that they can not be selectively re-closed and re-opened after the initial opening and must be refitted before subsequent use to drill another pile. Another disadvantage of at least some of these devices is their dependence upon an initial surge of grout pumping pressure. It is of course preferable to inject the grout at constant pumping pressure.

It is an object of this invention to provide means to selectively open and close the fluid passage in a hollowshafted auger of the type described which does not require the replacement of any operable parts for subsequent use.

It is another object of this invention to provide a device of the type described which will minimize the amount of adulteration of the initially injected grout.

It is still another object of this invention to provide a device of the type described which can be used to close off and open the flow path repeatedly and selectively.

Yet another object of this invention is to provide a device of the type described in which the build-up of hardened cementitious material will be minimized.

The manner in which these and other objects and advantages of the invention may be achieved will be apparent to those skilled in this art from a consideration of this specification in conjunction with the appended drawing.

BRIEF DESCRIPTION OF DRAWING In the accompanying drawing, FIG. 1 is an exploded view of an embodiment of the instant invention attached to the axial extremity of a hollow-shafted auger such as is known for use in placing cast-in-situ piling.

FIG. 2 is an elevation of the same device as shown in FIG. 1, shown fully assembled.

FIG. 3 is a cross-sectional representation of the device shown in FIG. 2 when viewed on section 4-4.

FIG. 4 is a cross-sectional representation of the same device taken along the same section, the device being shown in the closed position.

DESCRIPTION OF A PREFERRED EMBODI- MENT OF THE INVENTION As may best be seen in FIGS. 1 and 2, auger 11 is of standard design having hollow shaft 12 and auger flites 13. Replaceable cutting teeth 14 are shown in phantom form on FIG. 2 attached by screw means 15 to cross bar 16.

The shaft 12 is cylindrical, its hollow interior defining fluid flow conduit 17. The axial extremity 18 shown in FIG. 1 is that which will be adjacent to the deepest zone of penetration of the auger into the soil or other medium into which it is being drilled.

The element 19 is defined as a cup means having a circumferential surface 20 adapted to telescope over axial extremity 18 of Shaft 12. A plurality of apertures 21 are cut into this surface. In the embodiment described, two apertures 21a and 21b are distributed apart on cylindrical surface 20 of the cup means 19. Elongated slots 22a and 22b are also penetrating the circumferential surface 20 of the cup means. Set screws 23a and 23b are adapted to be screwed into screw holes 24a and 24b after passing through slots 22a and 22b, respectively, of the cup means, the heads of these set screws thereby slideably affixing the cup means 19 adjacent the axial extremity 18 of the shaft 12.

It will be seen that when the cup means 19 is telescoped over the axial extremity 18 of the shaft 12 to abut thereagainst (as shown in FIG. 4), apertures 21 will provide no communication between the conduit 17 formed by the hollow shaft and the outside of the auger, thereby effectively closing the conduit to the passage of fluid. This closing effect is accentuated by the sealing action provided by axial extremity 18 of shaft 12 setting against abutting surface 25 of the cup means 19.

On the other hand, when the cup means is axially extended away from axial extremity 18 of shaft 12, apertures 21a and 21b of cup means 19 permit fluid to flow freely from conduit 17 to the outside of the auger adjacent to the Zone of deepest penetration of the auger 11. It is desirable that the sum of the cross-sectional areas presented by apertures 21in the embodiment illustrated, apertures 21a and 21bbe at least as great as the crosssectional area of the conduit 17 so that there be no constriction in the flow path at the point where the cementitious grout flows out of the auger. In fact, it is most desirable that the sum of the cross-sectional areas of apertures 21 be greater than the cross-sectional area of conduit 17.

The reason that constriction in the flow path is to be avoided if at all pssible is that any such constriction may lead to the build-up of hardened cementitious material just up-stream of any such constriction. A further aide in preventing the occurrence of such build-up is to provide flow-directing surfaces 26 and 27 in the bottom of the cup means, whereby the flowing cementitious material will be directed toward apertures 21a and 211), respectively. The cup means may also serve as the anchoring point for the principal cutting tool of the auge such as fishtail bit 28 shown in the drawing. Inasmuch as this cutting tool undergoes a great deal of wear, it is further desirable to anchor it in the cup means in replaceable fashion with retainer pin 29.

In the embodiment shown, the auger shaft 12 is cylindrical in cross-section, so that cup means 19 is also required to have a cylindrical circumferential surface 20. The inner diameter of this cylindrical surface is desirably just sufficiently greater than the outside diameter of shaft 12 to provide an axially sliding fit between these elements.

Set screws 23:: and 23b cooperating with elongating slots 22a and 22b respectively permit the cup means 19 to be slidingly axially displaced relative to the axial extremity 18 of shaft 12 through a limited amplitude between the fully opened and the fully closed position. It will be noticed that apertures 21 are located axially on said cup means so as not to protrude in an axial direction beyond the confines defined by elongated slot means 22a and 22b.

In use, the means of the instant invention may operate as follows: Auger 11 is sunk into the soil at the location at which a pile is to be placed. Rotatory power for the auger is provided by conventional means not shown. The resistance of the soil to penetration by the auger keeps cup means 9 in the closed position a sshown in FIG. 4, i.e. telescoped upward to abut against axial extremity 18 of auger shaft 12, during this phase of the operation. When the auger has been inserted to the desired depth, retractive force is applied thereto at the driven end thereof (the end not shown in the drawing) and grout is pumped (by means not shown) into conduit 17. The combination of the retractive force and the grout pressure forces cup member 19 into its extended position, permitting grout to flow outward through apertures 21 into the hole formed by the auger. Should it prove necessary to re-apply force in the direction of drilling upon the driven end of the auger, cup member 19 would again be telescoped in the direction of its closed position on the end of the auger shaft.

The method of the invention just described produces unreinforced piling. The method can be adapted to the 4 placing of reinforced piling by pumping a non-cementitious fiuid (such as a bentonite slurry) into the hole formed by the auger, then placing a cage of reinforcing steel therein, and finally replacing the non-cementitious fluid in the hole with a cementitious grout.

It will be understood by those skilled in this art that other embodiments of this invention are within the scope and spirit of this disclosure.

I claim:

1. In an auger for placing cast-in-situ piling, said auger having a hollow shaft which defines a conduit for the passage of fluid material to that axial extremity of said shaft which is adjacent the zone of deepest penetration of said auger, means for selectively opening and closing said conduit at the said axial extremity comprising:

cup means with a surface configured to mate with a similarly configured surface of said extremity of said shaft,

at least one aperture in the circumferential surface of said cup means,

means slideably connecting said cup means in telescoping relationship to said shaft such that the configured surface of said cup means and said shaft surface are telescoped together and permitting said cup means to be axially displaced from a position abutting said extremity and effectively sealing said conduit to an axially extended position in which said aperture provides a How path from said conduit out of said auger at said zone of deepest penetration,

and smooth surfaced flow directing means positioned in said cup means to direct said fluid material to said aperture and prevent flo-w restrictive buildup of said fluid material in said cup means.

2. The means of claim 1 wherein the sum of the crosssectional flow areas through said apertures is at least as great as that through said conduit.

3. The means of claim 2 wherein the sum of the crosssectional flow areas through said apertures is greater than that through said conduit.

4. The means of claim 1 wherein said shaft and the circumferential surface of said cup means are of cylindrical cross-section and wherein the said circumferential surface of said cup means has an inner diameter only sufficiently greater than the outer diameter of said shaft to provide a sliding fit therebetween.

5. The means of claim 4 wherein two of said apertures are separated 180 apart on said circumferential surface. of said cup means.

References Cited UNITED STATES PATENTS 58,953 10/1866 Osgood 232 1,295,166 2/1919 Hoffmann 61-36 1,984,265 12/ 1934 Hamer 1117.1 3,300,988 1/1967 Phares 61-63 FOREIGN PATENTS 197,116 4/ 1958 Austria. 104,953 6/ 1924- Switzerland.

JACOB SHAPIRO, Primary Examiner U.S. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 529,428 Dated Sept. 22, 1970 Inventor(s) John Earl Batten It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 16, "pssible" should be "possible" Column 3, line 37, slots of 22a and 22b "of" was omitted Column 3, line 50, "9" should be "19" Column 3, line 50, "a sshown" should be "as shown" .1.". .LiD

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